example of stormwater drainage design This chapter provides guidance on storm drain design and analysis. The location of stormwater drains in relation to the sanitary drainage system. Preliminary Drainage Report (Step 2) 4 The only permissible drainage outlet is a natural drainage channel which has a capacity of 15 cfs and currently drains the area of development. 1. All planning and design must provide control of storm drainage with regard to quantity and quality to protect the health, safety, welfare, and property of the citizens and the City. DESIGN STANDARDS FOR STORMWATER DRAINAGE 5. 04) Following are design intensity-frequency-duration rainfall relationships for the City of Swan urban areas and Bullsbrook/Gidgegannup rural areas. 3 Road Drainage Storm drain pipes should not be located under athletic or recreation fields. A. This spreadsheet calculates the maximum flow from a specified linear drainage channel and checks whether the channel is sufficient for the specified site and storm conditions. 2 Other Stormwater Designs 16 9. Unless stream gage data is available for the project site, use of the USGS Regional Drainage is the collection, conveyance, containment, and/or discharge of storm water runoff. 2. MANUAL . Design Criteria ♦ 4. On this site the developer is required to provide control for the following: Recharge (Based on soil type) Water Quality (90% event) Channel Protection; 10-year Flood Control STORMWATER DRAINAGE DESIGN TO MASMA-EXAMPLE CALCULATION-ln I(30) = 5. The aspects of storm-drain design such as system planning, pavement drainage, gutter-flow calculations, inlet spacing, pipe sizing, and hydraulic grade line calculations are discussed herein. Documentation of Drainage Design . 1 below) is for an ,QVWLWXWLRQDO 8VHfacility and is comparable to a small hotel or conference center. are “Deemed to atisfy” S documents listed in Part B3 of the PCA and both contain sections “Surface and Roof Drainage on Systems - design”. Concept for the design of detention/retention facilities is also discussed. Descriptions of Each Drainage Management Area . 203-2. Please utilize these checklists to generate the necessary drainage report for your project. Preliminary Concept Development ♦ Design Checklist ♦ 1. 4 Example of Multiple Pond System P-4 RISER EMBANKMENT EMERGENCY SPILLWAY STABLE OUTFALL CELL 1 (FOREBAY) CELL 3 (WET POOL) INFLOW 10 YEAR LEVEL CELL 2 (WET POOL) AQUATIC BENCH SAFETY M AI N T E N A N C E A CE S R O A D CELL 1 (FOREBAY) OVERFLOW landscaping. 5. 3 Guidebook Design Manual The MSD Design Manual is a guide for the planning and design of stormwater systems, flood protection works, sanitary sewers, erosion control structures, small sanitary pump stations, small wastewater treatment plants and associated activities MSD. For example with a catchment area of 100sqm and a Coefficient of runoff of 0. As an example, let’s examine the following design scenario: Focus year is 2043 – 25 years in the future to account for sea level rise. Design Storm, 10-Year Event - A runoff, rainfall or flood event, having a ten percent (1 0%) chance of occurring in any given storm event. Outfall Considerations and Features ♦ 5. STORM DRAINAGE DESIGN . This example includes the following three-step process: Step 1 See full list on brighthubengineering. Y. This design example demonstrates the hydrologic and hydraulic computations to achieve water quality and water quantity control for stormwater management. Other design suggestions. The V=KA approach These systems are to complement the ability of the site design and structural stormwater controls to mitigate the major impacts of urban development. The construction checklist in Appendix B of the BASMAA Post-Construction Manual will be adapted and used to guide inspections during construction of the facilities. The swale is vegetated with flood tolerant, erosion resistant plants. This section of the TOHS Engineering Design and Construction Standards is intended to assist developers, engineers, contractors, inspectors and property owners in the selection of s for the design of new or existing facilities to improve the SCM requirement using drainage area and soil texture information; Step 5: Prepare a site plan depicting location of all proposed stormwater treatment practices, drainage areas, stormwater flow paths to each practice and other required elements detailed in the checklist on page 17 of this document. Reference Number: PWES-005. 7. North Country Automotive Site Plan. POND DESIGN EXAMPLE. Design Issues (3 to 8 inches) • This range of rains can include drainage-design storms (depending on rain intensity and site time of concentration). 4 Part-full pipe flow 149 Storm Water Inlets • These are the openings through which the surface runoff and storm water is admitted and conveyed to the storm water sewer or combined sewer. The amount of stormwater the catchment will produce can be determined with the formula (adapted from 49): Q des = 2. 1 Minimum Drainage Area . • County drains. 0112 (ln 60)³ Urban Drainage Design - Requirements Rainfall data:For design of a drainage system, the conventional pppppractice is to choose an appropriate, statistically relevant design storm to establish the stormwater flows to be conveyed, based on existing national & international practices. Depending on the design, they can also enhance stormwater quality by incorporating design components to promote sedimentation, Chapter 9 STORMWATER DESIGN CRITERIA . The objective of urban storm drainage is to optimize safe passage of vehicle traffic by collecting stormwater from the roadway, and to convey it safely to an adequate receiving body without undue risk to pedestrian traffic or contributing to damage of adjacent private properties during the design storm event. Several examples are presented to illustrate the detailed procedures for designing storm drainage system of a parking lot. 2 Runoff Curve Number 2. The following are some of the key issues in integrating water quantity and quality control consideration in stormwater drainage design. The massive increase of in-fill housing, large commercial areas of sealed impervious land cover preventing natural drainage, and water shortages have forced councils and government to find better solutions for dealing with storm water. Outfall Considerations and Features ♦ 5. 1, MSMA). Even where an open drain system is used, the inlets connect to the open The goal is a design that is the most cost-efficient while still satisfying the criterion described below. Performance Criteria for Urban BMP Design . The last step in the design of sanitary drainage systems in buildings using DESAGÜES (DRAINS) is the sizing of the Building (house) Drain pipes. Ken MacKenzie, Manager, Urban Drainage and Flood Control District 8. HYDRAULIC DESIGN CRITERIAFORDRAINAGE RELATED STRUCTURES 3. 1 Rational Formula 2. Storm Drainage Design and Technical Criteria. The preferred plat size is 24"x36", however an 18"x24'' plat size is acceptable for small basins. 2. Combined sewers can cause serious water pollution problems due to combined sewer of the major drainage system that capable of passing the storm runoffis from major storms. The following criteria shall be used for drainage system design. Required : Minimum volume of Storm Water Detention Basin. Temporary stormwater drainage for road construction RMS 11. Preliminary Concept Development ♦ Design Checklist ♦ 1. Revised 12/16 STORMWATER MANAGEMENT & DRAINAGE DESIGN Page 5- 1 . This requirement ensures that the permanent pond cab be maintained by the runoff from the contributing drainage. Storm Drainage Structures. *Design procedures and detailed examples are presented for drainage channels, flow transitions, and energy dissipates *Many computer models are introduced that can be used in the design of various components of stormwater collection systems *Water quality aspects of stormwater collections systems design are discussed See full list on fao. 8 x C x i x A Q des: the design peak runoff rate, or the maximum flow of stormwater the system will be designed for (in litres per second) C:the runoff coefficient (see table F. Even the most basic pump station serving a small catchment requires a For example, the sandy soils in the flat terrain of coastal Florida rarely have problems with standing water, because the high sand content lets water drain freely. 2. 1086 + 0. that form part of the receiving drainage system) whose capacity may be impacted by stormwater runoff discharging from the proposed land development. 00, and the Water Quality Regulations, 314 CMR 9. STORMWATER MANAGEMENT & DRAINAGE DESIGN . The design of a drainage system must address the needs of the traveling public as well as those of the local community through which it passes. a review of existing Tucson Stormwater Management Study (TSMS) data, roadway hydrologic data, and existing and proposed drainage infrastructure. Some components of WSUD may conflict with local government drainage regulations. The issues that stormwater management are intended to address can be categorized as water quality or water quantity issues. • Section 8. Design of Forebay and Micropool for Highway Stormwater Detention Basins 5. 1 Purpose of the Chapter The purpose of this chapter is to provide guidance for designing facilities to detain stormwater runoff from Stormwater management by road drainage, stream erosion control and stormwater quality management have been included in the Project generally in accordance with the New Zealand Transport Agency’s (the Transport Agency) Environmental and Social Responsibility Standard (Z/19) for new project works. Because of ongoing regulatory and technical changes in the fields of floodplain and stormwater management, revisions to this manual will be required from time to time. There are a number of Example . The SWM report must identify the design criteria for the components of the highway drainage system (i. 1 Construction Activities Stormwater Manual (PDF, 348KB) Last Updated: 6/1/2010 . In many instances, stormwater problems signal either misuse of a resource or unwise land activity. 2155 (ln 60)² + 0. IV. This course covers the basics of designing an adequate storm drainage system for a parking lot. The project will satisfy this requirement in the following ways: Roof Surfaces – The main roof of the home will drain via 4 downspouts located as shown on the attached site plan. ) is designed to safely contain, Chapter 1 - 3 a review of existing Tucson Stormwater Management Study (TSMS) data, roadway hydrologic data, and existing and proposed drainage infrastructure. e. a. C. The drainage system consists of all natural and man-made features that collect or receive concentrated stormwater flow. 6 = 60 sqm. Design methods are presented for evaluating rainfall and runoff magnitude, pavement drainage, gutter flow and drainage inlets. Runoff hydrographs 5. The scope of this chapter is limited to the drainage design responsibilities of the Project STORMWATER DESIGN MANUAL Effective Date: December 31, 2016 Thanks to the Following for Their Examples and Preservation of Natural Drainage Systems and experience regular storms. 04/20 Download CULTEC Stormwater Design Calculator v. The various components which affect runoff are presented along with seven methods for estimating the amount of runoff from a rainfall event. The first source to discuss is raw stormwater runoff, where the stormwater flows straight from a drain or collection system into the pump station. 9 Areas of ponding. PHRC. For t = 60 minutes; ln I(60) = 5. 4 West VirginiastormWatermanagement & DesignguiDancemanual Treatment Volume for Drainage Area A from the Site Data Tab in the West Virginia Compliance Spreadsheet or the following equation: Equation 3. through access chambers, junctions, catch pits etc. paved surfaces, buildings, etc. Proposed Changes to Stormwater Manual and City-County Code The Indy DPW stormwater engineering staff is currently preparing to formally propose changes to both the Indianapolis Stormwater Manual and various sections of the Indianapolis-Marion County City Stormwater ponds should have a minimum contributing drainage area of ten acres or more (25 or more are preferred), unless groundwater is confirmed as the primary water source (i. DESIGN IFD CURVES FOR CITY OF SWAN (Section D5. These are examples of attractive and water-friendly alternatives to conventional stormwater management practices. A. design variances MAY be worked out through Private Development Section (i. and the direction stormwater flows from the downspouts. 5037 ln (60) – 0. The minimum drainage area contributing to a vegetated swale is not restricted. 1 For contributing drainage areas of 100 acres or greater, the SCS Unit Hydrograph Method shall be used as a minimum. Information is provided herein to provide a qualified designer with consistent and Overview of stormwater design practices for construction activities. From auger hole tests, the hydraulic conductivity above this layer was estimated as 0. Minimise the area of impervious surfaces such as 2. This is not as common as traditional drainage systems, mainly due to the high up-front cost of these systems. the stormwater drain discharging into the sewer system. 1086 + 0. of stormwater runoff should not be preparing or reviewing the engineering designs for the measures discussed in this document. The following design example is for the "wet extended detention (ED) pond," from STP Group 1 (stormwater ponds). The modified FAA Method . 3 which details a solution to stormwater drainage philosophy of lessening the impact of stormwater flow through and off developed areas. 5. com Introduction. This design example illustrates the design of a dry extended detention stormwater basin that provides water quality treatment and peak discharge control within a highly impervious com-mercial development. The following hypothetical examples illustrate various components of an integrated site design and stormwater management planning process and how this process can be implemented for different types of land development projects: 3. 6 (60%), the area to enter into the program is 100 x 0. A. . 2 Runoff generation 96 6. 2 Building drainage 119 7. Utility Conflicts ♦ 6. 3 Time of Concentration 2. 1 Introduction 134 8. Stormwater Pond Design, Construction and Sedimentation. 5 Plumbing and drainage - Part 5: Housing installations. 8602 Rosemary Street Commerce City, Colorado 80022 303-289-8170 The allowance for possible stormwater discharges from adjacent properties, 2. See the design examples in Chapter 2, Section 2. Storm Water Catch Basin Drainage SystemProtecting your home from rain water and runoff is a high priority. 1 INTRODUCTION AND PURPOSE These standards are meant to interpret and clarify the Stormwater Design Guidelines of the Town of Clayton. Ensure that there are no illegal cross connections of sewer and stormwater drains. Background The City of Melbourne manages an extensive network of stormwater drainage assets, made up of approximately 365 kilometres of underground drain and 15,000 drainage pits. 2 Stormwater Management Design. This Builder Brief will outline the design, sizing, and construction considerations for dry wells. 2 contains a significant amount of design guidance that the designer should use to integrate robust and cost-effective stormwater management into site designs in ways that achieve the Philadelphia Water Department's (PWD’s) key stormwater management goals of minimizing the harmful effects of flooding and maintaining the health of Philadelphia’s 8 design of short length culverts under embankments page 21 9 calculating time of concentration page 21 10 examples of calculating the runoff coefficient c page 22 11 method of stormwater reticulation design page 24 12 general methodology page 24 13 worked example page 27 revision date: may 2008 3 Example 1: Standard SMR Compliance (25% Retention / 25% Detention) This example site has one connection to the Combined Sewer System. Stormwater Drainage Design for Parking Lots ACE Group, LLC Course Outline Parking lots can be seen almost everywhere, from shopping centers to office buildings to schools. • Establishes energy gradient of streams A design by a registered professional may be required for more complex sites. 2 DESIGN DOCUMENTS Broadly, the hierarchy of technical documents to be used for drainage purposes is as follows: - Stormwater Management Issue Reference Policy, Planning, Legal and Technical Requirements Pine Rivers Shire Planning Scheme Minor and Major drainage design methodologies Queensland Urban Capacity: The capacity of a stormwater drainage system is the flow volume or rate that a facility (e. 3 Time of Concentration 2. Using arrows, show the direction of stormwater flow off of impervious surfaces. Indicate Figure 1. ) P = Depth of target rainfall event = 1” Rv I APPENDIX 1: Post-construction Design Examples 3 Section A: Dry Extended Detention Basin Figure 1. 8 m below the surface. 2 presents a pond design example based on the hydrology calculated in Section 8. our services are ideal for projects that require temporary collection and storage of stormwater runoff - from stormwater management systems. 1 m are used. 1 Design of Enclosed Storm Drain Systems Stormwater Management Design Manual contains guidance for designers in order to assist them in meeting those requirements. Planning scheme policy – stormwater drainage design v1. 2) DESIGN EXAMPLES 2. The objectives for stormwater planning, stormwater quantity and quality considerations, Stormwater inlets, also known as gully inlets, are mainlyand maintenance problems. An excellent example of a filter strip is the riparian buffer zone, where a sensitive stream system is buffered drainage from highways as well as from buildings. estimating storm water runoff discharge rates and/or volumes from precipitation for the design of the highway drainage system and any required cross drainage structures. 3 Hydrologic Evaluation For Detention Pond Sizing Three hydrologic methods were used to establish the required detention pond size: 1. If proper water drainage is not installed, then st For example, increasing the size of an existing cross culvert introduces more storm water flow rate to downstream property owners. Reference Number: PWES-005. psu. 29. In general, only computed peak flow rates will be requiredfrom the hydrologic analyses. 101. pdf means to install a new drainage pipe or ditch or make improvements to an existing drainage pipe or ditch, for purposes other than maintenance, that either serves to concentrate previously unconcentrated surface water or stormwater runoff or serves to increase, decrease or redirect the conveyance of surface water or stormwater runoff. V Stormwater Drainage Well must submit a notification form to the NC Division of Water Resources’ Underground Injection Control (UIC) Program in order to comply with federal injection well inventory reporting requirements. Chapters C-1 through C-12 were updated on November 20, 2020. Local officials seeking guidance on developing stormwater controls are encouraged to visit the " Think Blue Massachusetts " website for information and resources. edu Stormwater Management Ordinance (2016). View sample report. HYDRAULIC DESIGN CRITERIAFORDRAINAGE RELATED STRUCTURES 3. Check Flood ♦ 9 Our advanced drainage design systems are created by experienced drainage specifiers and engineers who can build custom catch basin designs based on your requirements. Where there is a superficial aquifer, drainage channels can include both stormwater from surface runoff, and groundwater that has been deliberately intercepted by the drains. If the site layout and underlying soil conditions permit, a portion of the Channel Protection Volume (V cp ), Overbank Flood Protection Volume (V p10 ), and the Extreme Flood Volume (V p100 ) may also be managed in the infiltration practice. 11. The Drainage Checklists were formulated from Chapter 4 of The Stormwater Management Manual. There are no other off-site or upstream tributary areas. If you have any areas where stormwater collects, such as drainage swales or ditches, show this and label them as such. Riser– A vertical pipe which extends from the bottom of a pond stormwater practice and houses the control devices (weirs/orifices) to achieve the discharge rates for specified designs. Stormwater Management and Calculations 3-2 July 2007 3. 1. Anytown, USA . 4 Conditions for Building over Common Stormwater Lines and Stormwater Easements 21 10 ON-SITE STORMWATER DETENTION 23 Step 3 – Preliminary Design Concept Design – Use micro-bioretention (M-6) Drainage Area 1 (DA 1) During the Concept Plan process, Equations 5. 3 System components 121 7. These calculations are to be submitted 3. System Design ♦ 8. It can be used as a stand alone design tool that generates report outputs based on your parameters. 3. Water quality issues deal with the degradation of runoff, and the protection of environmental resources. includes guidance on better site design practices, hydrologic techniques, criteria for the selection and design of structural stormwater controls, drainage system design, and construction and maintenance information. All storm drainage facilities shall be designed in accordance with these Standards, accepted engineering principles and state and federal water quality regulations. Ribbon curb, or curbless streets, sloped to vegetated areas, allow rain from streets to drain into raingardens or vegetated swales on adjacent property. 1 General 15 9. Performing Organization Report CDOT-2016-05 9. 1 Rainfall - 2. 1 (Examples of Source, Pathway and Receptor solutions Source: Managing Urban Runoff - Drainage Handbook, PUB 2013) Technical Guide for On-site Stormwater Detention Tank Systems channels, storm sewer systems, stormwater detention, culverts and bridges, stormwater pollution protection, as well as requirements for maintenance and operation of drainage facilities. The policy for stormwater quality management (including erosion and sediment control and acid sulfate soil management) is the Planning scheme policy – healthy waters. D4. Given the drainage area, select the appropriate swale practice for the first iteration of the design process. Ribbon curbs. ) increase the volume of surface runoff in a watershed because they prevent rain water from infiltrating into the soil. 1). Connect either temporary or permanent downpipes. Stormwater retention ponds are designed to minimize the adverse effects that impervious surfaces have on watersheds. Water Quality Volume: Follow the GDOT Drainage Design for Highways Manual to size the The CULTEC, Inc. The systems used to drain stormwater are often referred to as storm drains, but they are also called storm sewers and drainage wells. This example is a 24"x36" paper size. CHAPTER 5 . 2. 1. Design Drainage Area Design Drainage Area: Every drainage study area will include any number of “Design Drainage Areas” that must be analyzed to determine the design storm flow for the purpose of sizing and placing stormwater management facilities of various types. 4 Stormwater quality 110 7 System components and layout 119 7. 2. The flow of the rainwater is typically off roofs, down drainpipes, through ground drainage, into underground pipes or other drainage systems and eventually into stormwater stormwater volume, erosion, sedimentation and other forms of stormwater pollution. Stormwater Ponds 3. 1 Commercial Office Building Development. 2. 0 INTRODUCTION 1. 0 CULVERT Example of a gutter and downspout roof drainage system (courtesy of Frontier Roofing). February 16, 2021 Page 1 TABLE OF CONTENTS Chapter 13: Drainage FACILITIES DEVELOPMENT MANUAL . Computations : a) Compound Run-off Coefficient. 1 Discharge into storm water channels or pipes Where a storm water pipe or ditch exists within reasonable distance of the property on a building site, the drainage from the roof and from any paved or enclosed areas must be collected and discharged into the storm water pipe or ditch. 0 Design Examples – Provides design examples for an extended detention basin, sand filter, and media filter drain. Connect either temporary or permanent downpipes. The Rational Method is widely used to estimate the peak surface runoff rate for design of a variety of drainage structures, such as a length of storm sewer, a storm water inlet, or a storm water detention pond. Maximum spacing depends on road surface, it varies between 30 to 60 m. Section 3. EPA's Storm Water Management Model (SWMM) is used throughout the world for planning, analysis, and design related to stormwater runoff, combined and sanitary sewers, and other drainage systems. The stormwater management approach for this example site consists of a lined Flow-Through Planter, Vegetated Roof, Permeable Pavers, and Rainwater Harvesting for use in toilets. The quality of the final in-place system usually reflects the attention given to every aspect of the design as well as that accorded to the construction and maintenance of the facility. 0 GENERAL . Problem Identification ♦ 2. DESIGN EXAMPLE 1: INSTITUTIONAL SITE PLAN Site Description: This example design (Figure 13. Managing stormwater better 3500. This example is a 24"x36" paper size. g. GENERAL 2. Stormwater, for both water quantity and quality, shall be designed in general by the criteria established herein, the City's Master Drainage Plan, the Virginia Department of Trans- Design Drainage Area Design Drainage Area: Every drainage study area will include any number of “Design Drainage Areas” that must be analyzed to determine the design storm flow for the purpose of sizing and placing stormwater management facilities of various types. Such revisions will be approved by the Floodplain Administrator. 1 September 2017 Urban Drainage and Flood Control District 12-1 Urban Storm Drainage Criteria Manual Volume 2 . , pocket pond). 3 Pipe flow 139 8. 11. These are the NRCS methodology, Examples: Stormwater Release Rates Examples: A typical one acre site in Brooklyn will be required to detain and release runoff at a rate of 0. Ensure there are no illegal cross-connections of sewer and stormwater drains, i. For example, the stormwater detention volume provided for a Examples of acceptable drainage outlets include, but are not limited to, the following: • Natural watercourses. It can be used to evaluate gray infrastructure stormwater control strategies, such as pipes and storm drains, and is a useful tool for creating cost It's a plumber's job to design a stormwater drainage system for your home that prevents flooding, and also prevents contaminants from entering stormwater catchment systems. 1 Introduction 96 6. Peak Flow Calculations Some of the state’s stormwater programs require providing attenuation of peak runoff; for example, that the post-development flow rate for the one-year, 24-hour storm may not exceed the pre-development flow rate (Neuse and Tar-Pamlico NSW Programs). 2 Basic principles 135 8. Other specific dam design criteria such as soil compaction, structural appurtenances, embankment drainage, outlet design, gates, reservoir drawdown 6. Surface drainage licensed professionals for the planning, design and construction of onsite source controls that comply with DEP’s stormwater performance standard. Ensure that there are no illegal cross connections of sewer and stormwater drains. 3 Disposal of Stormwater from Development Sites 16 9. 4 Design 129 8 Hydraulics 134 8. For highway purposes, a natural watercourse is defined as one that has not been altered artificially. NCDEQ Stormwater Design Manual _____ _____ C-1. System Plan ♦ 3. 1 STORMWATER DRAINAGE DESIGN OVERVIEW See full list on trimediaee. This can vary SECTION 11 - DRAINAGE DESIGN CRITERIA 1. e. The design techniques in this section are meant to maximize the volume of stormwater being infiltrated. Values for the runoff coefficient, drainage area, time of concentration and design return period are needed. The section responsible for design of the drainage structure shall also design the related stream bank stabilization and erosion control. The engineer shall ensure that Council’s requirements relating to stormwater quality management, erosion and sediment control and acid sulphate soils are provided for in the stormwater design. 25 cfs. 1 through 5. This example prepared by Dan Cloak Environmental Consulting to assist users of the Contra Costa Clean Water Program’s Stormwater C. Volume 1 lays out the legal and regulatory framework for the Handbook. e. 2 Executive Summary Chapter 3. During a major storm event, the excess stormwater will accumulate in and be carried through the street gutters. com See full list on brighthubengineering. DRAINAGE CRITERIA MANUAL DETENTION DESIGN City of Bella Vista, AR DET-1 1. The design of a drainage system must address the needs of the traveling public as well as those of the local community through which it passes. The The objectives of stormwater drainage design are as follows: (a) To ensure that inundation of private and public buildings located in flood- prone areas occurs only on rare occasions and that, in such events, The Stormwater Handbook was revised and updated in February 2008 in accordance with revisions to the Wetlands regulations, 310 CMR 10. 2 Executive Summary Stormwater consists of rainfall runoff and any material, soluble or insoluble, that gets swept up in its flow. 0 Page 3 1. 8 m below the soil surface. This can vary ♦ Overview of Urban Drainage Design ♦ Overview of Storm Drain Design 2. e. The use of Best Management Practices for stormwater can be a cost-effective means to protect our water resources. Current version is: v. For a Residential SubdivisionProject . Proper street drainage design requires that public safety be maintained and any flooding bemanaged to minimize flood damage. org July 2008 Highway Drainage and Stormwater Management 6-3 • Stormwater quantity and quality management. Plumbing Regulations 2008 also specify that Grassed Swales. 2. Table 1provides the basic acreage and site hydrology. 1. More specifically, it provides specific, detailed design and performance methodologies designed to meet the water quality and quantity requirements of stormwater management systems. The Stormwater Program will periodically update the Manual to provide better guidance on meeting the stormwater rules. The City of Oceanside is responsible for local administration of storm water management requirements and has developed a Best Management Plan (BMP Design Manual) as a resource document, which is designed to facilitate the implementation of the requirements of the RWQCB Municipal Separate Storm Sewer System (MS4) Permit. , pipe, pond, vault, swale, ditch, drywell, etc. 1 GUIDELINES FOR HUMAN SETTLEMENT PLANNING AND DESIGN Stormwater management Chapter 6 stormwater volume, erosion, sedimentation and other forms of stormwater pollution. Drainage design of existing facilities shall not be modified unless a flooding problem is identified or if the existing design is incompatible with the proposed facilities. Analysis shall be based on a Type II 24-hour rainfall distribution. Example problems are used to illustrate the use of the procedures. Drainage areas with shorter times of concentration will have higher peak runoff rates than those with a longer Tc. The stormwater performance standard was promulgated on [DATE] as an amendment to Chapter 31 of Title 15 of the Rules of the City of New York, Rule Governing House/Site Con- Chapter 8 Example Stormwater Plan Each chapter contains the equations, charts, and nomographs needed to design specific stormwater management facilities. 3. The purpose of this document is to outline the stormwater drainage design requirements for developments within the City of Melbourne. The design of grassed swales promotes the conveyance of storm water at a slower, controlled rate and acts as a filter medium removing pollutants and allowing stormwater infiltration. All areas that will be considered natural cover for stormwater purposes must have documentation that prescribes way for a single-family home to meet local stormwater ordinances. 02 OBJECTIVES 1. 4. 1 (Chapter 3): Where: Tv = Target Treatment Volume, in acre-feet (ac. 1 through 5. Also, pollutants that collect on impervious surfaces are not filtered by the soil or plants and are conveyed directly to rivers and beaches without Complete the final stormwater drainage system before the roof is installed. The aspects of storm-drain design such as system planning, pavement drainage, gutter-flow calculations, inlet spacing, pipe sizing, and hydraulic grade line calculations are discussed herein. Design Drainage Area Design Drainage Area: Every drainage study area will include any number of “Design Drainage Areas” that must be analyzed to determine the design storm flow for the purpose of sizing and placing stormwater management facilities of various types. A grassed swale is a graded and engineered landscape feature appearing as a linear, shallow, open channel with trapezoidal or parabolic shape. The . Highway Design Manual, Chapter 8 Highway Drainage. 3 in the Design Manual may be used to provide a quick estimate of the amount of rainfall that may be treated in a given practice when the surface area and drainage area information is known. 2155 (ln 30)2 + 0. 4 Trunk Drainage 13 7. 3 in the Design Manual may be used to provide a quick estimate of the amount of rainfall that may be treated in a given practice when the surface area and drainage area information is known. 6 P-4 Figure 3. The Massachusetts The SWM report must identify the design criteria for the components of the highway drainage system (i. In considering a cost-efficient drainage design, the initial cost should be considered, but facility longevity and future maintenance costs and legal and environmental constraints should be considered also. ) STORMWATER DRAINAGE MANUAL SECTION 3 Drainage Manual: File Name. There are no perennial or intermittent streams or any other water bodies within or adjacent to the site. New York State Stormwater Management Design Manual (January 2015) contains the technical standards for stormwater management. 1-2 Columbia County Stormwater Management Design Manual Chapter 2 Section 2. 101. 2 ADDITIONAL GUIDANCE The PWQ Program directs the need for PWQ CMs as well as the design and installation of PWQ CMs. No BMPs were found to be infeasible. Examples of common level spreaders include: concrete sills (or lips), curbs, earthen berms, and level perforated pipes discharging to the surface or sub-surface. our services are ideal for projects that require temporary collection and storage of stormwater runoff - from stormwater management systems. Drainage design storms of these depths would last only for a few hoursonly for a few hours. e. Shallow Marsh– Human-made wetland with water depths ranging from <6” to 18”, planted with native wetland vegetation. January 2021 Roadway Design Bulletin - 2021 Drainage Manual: 10/30/20: DrainageManual2021. 3 Planning Concepts construction, and must follow the most recent design specifications for soil restoration and, if applicable, site reforestation, as well as other relevant specifications if the area will be used as a BMP. Detention storage facilities manage stormwater quantity by attenuating peak flows during flood events. 16. 1. Consistent with the 2013-2018 Western Washington Phase II Municipal Stormwater Permit, the City of Olympia has adopted a revised Drainage Design and Erosion Control Manual (DDECM) along with other revisions to sections of the Olympia Municipal Code and Engineering Design and Development Standards (Ord. Examples of exceptions are firefighting activities or water utility line flushing. Version 04/20 Volume II is applicable only to those ERP activities that involve the design of a stormwater management system that requires a permit under Chapter 62-330, F. e. 2) Why is this required? The goals of the storm water site plan are to protect water quality, reduce water run-off, and to prevent erosion. 1. 1. The design storm for calculating the required storage volume, termed the storage design storm, shall be 10 year ARI. Introduction. Sometimes people confuse stormwater drainage systems with sanitation sewers, but storm To evaluate whether your stormwater system will achieve the desired level of service during a coastal flood event, you must first define your design scenarios. In NCSU Stormwater ODNR Rainwater and Land Development Manual (2006) ODOT Location & Design Manual, Volume 2 Drainage Design Ohio EPA Construction General Permit Ohio EPA Map of Construction Stormwater Permits Ohio EPA Storm Water Pollution Prevention Plan (SWP3) Checklist for Construction Activities (OHC000003) Home | Glen Eira City Council In addition to the contributing drainage area’s impervious cover, a number of site constraints must be considered when the implementation of a grassed swale is proposed. 4 Flood Routing 3. For information on permeable pavement systems, design specifications, operation and maintenance and case studies, go to the Minnesota Stormwater Manual. Construction ♦ 7. TECHNICAL CRITERIA . 7027). Part II — Methodologies and Design Examples The methodologies in this Part II are intended to aid applicants in designing stormwater management systems Stormwater Drainage Design 2. 10. 1 Design of Enclosed Storm Drain Systems Section V: Design Requirements For Stormwater Management Systems 1. Overview of Urban Drainage Design. Virginia Stormwater Management Handbook, Chapter 13 July 2013 Design Example 1 11-6 13. MR #5 On – Site Stormwater Management – The applicant chooses to meet this requirement with the List Option. Stormwater should be considered a resource (see Figure 6. METHODS OF DETERMINING DESIGN DISCHARGE 2. 9 mm/hr. February 21, 2018 . Drainage System For purposes of regulation, the drainage system shall be divided into geographical and functional groupings. This is the drainage system´s component that receives the discharge from soil and waste stacks and, also, from other drainage pipes (usually horizontal branches on the buildings’ ground level) and practical to drain stormwater through, and then approach the owner(s) to request an easement be granted for the purpose of draining stormwater to Council’s drainage system (refer Attachment 1 - Sample Letter). This course covers the basics of designing an adequate storm drainage system for a parking lot. A stormwater drainage system can be as simple as a ditch that outlets to a stream or as complex as a system comprising numerous intakes, manholes, and Volume 2 (Technical Handbook) Georgia Stormwater Management Manual 5-1 CHAPTER 5 STORMWATER DRAINAGE SYSTEM DESIGN Table of Contents SECTION 5. Consult with the UNC Stormwater Engineer during schematic design if this is infeasible. Whispering Pines Lane . Unified Stormwater Design Guidelines TABLE OF CONTENTS STORMWATER DESIGN GUIDELINES Page 2 of 4 TABLE OF CONTENTS Effective February 2007 As Revised August 2012 B. 068 December 2011 Page 1 Printed copies of this document are uncontrolled 1 PURPOSE The purpose of this Guideline is to provide design considerations and example drawings to assist Roads and Maritime Services (RMS) and contractor project management teams to plan and design Modern Stormwater Drainage Systems. The Stormwater Design Manual is compatible with the Minimum Design Criteria (MDC) that are codified in the stormwater rules, which went into effect on Jan. 16. For stormwater system design, a drainage area (A) is the combined area of all surfaces that drain to a given location such as a swale, intake or culvert inlet, pond, stream, etc. 1 Rational Formula 2. Many storm drainage systems are designed to drain the storm water, untreated, into rivers or streams. 6 Example Problem the design manual describe the regulations applicable to stormwater management and drainage design in the City of Raleigh and provide _____ Design Standards for Stormwater Detention and Retention for Pima County I REVISIONS . DRAINAGE CRITERIA MANUAL (V. This report serves as documentation of all the design flow rates tributary to the Grant Road Project that will be used to size the recommended drainage improvements included in the roadway design. Inland parts of Florida, also with flat terrain but with richer organic soils that hold water, are more likely to have problems with standing water after a storm, because the soil does not drain as easily. 1 Introduction 119 7. pdf. 2. Effective Hydraulics and Stormwater Design emphasizes stewardship of California's water resources by providing: Development and maintenance of guidance and state-of-the-practice information for departmental staff to promote uniformity and consistency in the design of roadway drainage-related features. Where appropriate desktop computer procedures are developed for design applications. XYZ Corporation Jane Jones, 925-555-1212 . Design storms can be estimated from rainfall data records The Municipal Separate Storm Sewer System (MS4) Differing from a Combined Sewer System (CSS), a Municipal Separate Storm Sewer System (MS4) is a system of water management and drainage that keeps stormwater separate from the sanitary sewage system that is meant to handle other forms of solid and liquid waste The Storm Drainage Design Standards (Standards) provide design criteria, standards, policies and procedures for storm drainage improvements within the City of Oakland. AND . This new series of webinars – Stormwater Drainage Design Fundamentals – covers the basic and intermediate aspects of the Three Waters modules in 12d Model 14, with special emphasis on the design of stormwater drainage. This manual is not an exhaustive and detailed design manual for stormwater hydrology information. DSD A "Small Parcel Stormwater Site Plan" is required whenever a building application is made for residential development with more than 2,000 square feet of new roof, paving, gravel, or parking area. Stormwater Control Plan . A drainage basin may consist of one or several drainage areas. A. Stormwater Management Concept 2 2. that form part of the receiving drainage system) whose capacity may be impacted by stormwater runoff discharging from the proposed land development. For additional guidance regarding Indy DPW design standards, view our DPW Design Memos. Problem Identification ♦ 2. Stormwater Design Calculator is an MS Excel-based spreadsheet used for designing CULTEC Stormwater Systems. 2 Unit Hydrograph Method 2. A signed Mylar is required after a paper copy is reviewed and approved. 8 m/day. Photo by Matt Royer, Penn State 9 Stormwater flow paths. 2. Description Date; RDB20-11. To correctly size the stormwater drainage system you will need to calculate the design flow of the stormwater in litres per second (L/s). 1 Construction Activities Stormwater Manual (PDF, 348KB) Last Updated: 6/1/2010 . 04/20. This section of the TOHS Engineering Design and Construction Standards is intended to assist developers, engineers, contractors, inspectors and property owners in the selection of s for the design of new or existing facilities to improve the SCM Examples: Stormwater Release Rates Examples: A typical one acre site in Brooklyn will be required to detain and release runoff at a rate of 0. Keep stormwater clean! Achieve a natural water balance in the design of the site. Overview . 1 Rainfall - 2. Author(s) James C. Volume Three, the Pollution Prevention Guidebook, is a compendium of stormwater pollution 6. Example 1. Sizing of Systems Examples of illegal discharges include: chemical spills, failing septic systems, overflowing grease traps, leaking trash dumpsters, washing paint or construction waste down the storm drain, and depositing pet waste into storm drains or ditches. Example of layout and sizing Figure 2 is from Appendix K of AS/NZS 3500. 2. -ft. g. These challenges also apply to BMP retrofit designs. CITY OF COMMERCE CITY. Check Flood ♦ 9 NJDOT Design Manual – Roadway 10-5 Drainage Design Stormwater is a component of the total water resources of an area and should not be casually discarded but rather, where feasible, should be used to replenish that resource. Conformity with these criteria will provide uniform performance of the storm drainage system as a whole. Stormwater drainage design is an integral component in the design of parking lots. Protection of buildings, and 3. Design Criteria ♦ 4. Reference Number: PWES-005. In these cases, footpaths and driveways and other impervious features are designed to drain evenly onto adjacent areas, not into a piped system. Examples are swales or channels Storm drainage systems for transportation facilities collect stormwater flowing within and along the highway right-of-way and convey it to a suitable discharge point. *These details are found in the document Managing Storm Drainage on Small Lots, The Small Parcel Stormwater Site Plan on the pages that begin with “Handout” PLEASE INITIAL BELOW TO INDICATE THE STORMWATER MANAGEMENT PLAN FOR THIS SITE drainage from highways as well as from buildings. 0112 (ln 30)3. channels, storm sewer systems, stormwater detention, culverts and bridges, stormwater pollution protection, as well as requirements for maintenance and operation of drainage facilities. Plans that involve discharging stormwater to county drain must be submitted to the County Drain Commissioner. 3 Overland flow 103 6. New York State Stormwater Management Design Manual (January, 2015) The New York State Stormwater Management Design Manual provides designers with a general overview on how to size, design, select, and locate stormwater management practices at a development site to comply with State stormwater performance standards. Planning for drainage and stormwater management facilities should include a . , pipe outlet encroaching SCPZ, drainage area diversions etc. 1, 2017. Storm Drainage Design and Technical Criteria. 1 Discharge into storm water channels or pipes Where a storm water pipe or ditch exists within reasonable distance of the property on a building site, the drainage from the roof and from any paved or enclosed areas must be collected and discharged into the storm water pipe or ditch. This can vary 10. IV. 1. Step 3 – Preliminary Design Concept Design – Use micro-bioretention (M-6) Drainage Area 1 (DA 1) During the Concept Plan process, Equations 5. com 1 4 1 Drainage Design Process 4 6 11 STORMWATER PUMP STATION DESIGN 96 A 2 1 C Adjustment Factor Example 147 Stormwater Drainage Systems . Complete the final stormwater drainage system before the roof is installed. The design storm for discharge from an OSD storage, termed the discharge design storm, shall be the minor system design ARI of the municipal drainage system to which the storage is connected (refer Table 4. 6. Whether it is a commercial mixed-use residential development or a commercial establishment, drainage design and stormwater management should take a crucial role in the planning and implementation process. 5037 ln (30) – 0. 5. You will use the design flow rate to determine the correct pipe size that will maintain the appropriate water velocity. Runoff Computation Methods As described in the Stormwater Management Rules, the NJDEP has specified that one of two general runoff computation methods be used to compute runoff rates and volumes. 2 General Drainage Design Considerations drainage and stormwater in the City of Aurora. 2. Storm Drainage Design and Technical Criteria. These constraints are discussed as follows. IV. The design of the on-site storm drainage systems will be included in the Final Storm Water Drainage Report. 2 Runoff Curve Number 2. the new or reconstructed portions of facilities. 2. • For a street with a valley gutter, another foot for the gutter is allowed with a total drainage area by means of suitably sized grass lined earth channels positioned within the proposed road reserves. System Design ♦ 8. " Multiple Drainage Areas: When a project contains or is divided by multiple drainage areas, the WQv volume shall be addressed for each drainage area. The peak storm water discharge from the property will be less than the undeveloped site’s peak Sample Stormwater Plan Narrative (Sample Project: 40 lot rural subdivision on a county road) Drainage Background: The entire subdivision is located in the Pewaukee Lake watershed of the Fox River basin. 7. Performing Organization Code 114. The earth channels will gravitate towards the identified detention areas, where stormwater will be attenuated in order to deposit any transported sediments and reduce the flow velocities. 2. SPDES General Permit for Stormwater Discharges from Construction Activity - NYSDOT is required to prepare and implement Stormwater Pollution Prevention Plans in Example For the drainage design of an irrigated area, drain pipes with a radius of 0. 25 cfs. Stormwater Planning Conference (Step 1) 2 1. 6 Stormwater 96 6. • Stormwater Concept Plan and consultation meeting are required early in the design process to discuss stormwater management requirements and to identify potential GI Practices • Allows use of previous Water Quality standard (80% total suspended solids [TSS] removal) ♦ Overview of Urban Drainage Design ♦ Overview of Storm Drain Design 2. It serves as a supplement to State and Federal design manuals that govern stormwater management design including the following: Virginia Stormwater Management Handbook, prepared by the Linear Drainage Design Spreadsheet. The function of stormwater drainage systems is to collect minor designstorm runoff and convey major design storm (flood) runoff to a discharge point. Flood risks and drainage are key considerations when planning 9 + 6c 1 ) % +7c 2 8 +9 c 8 # 1 , % ˝ $+ ˛/ % ˝$+ %˛ ˛7 ˙ ˘ ˘ ˆ bˇ ˆ˘ ˜ ˝˚0˝0 ˚˘ ˆ ˙ ˘ ˘ ˆ bˇ ˆ˘ ˜ stormwater runoff in dry cells. Keep stormwater clean! Achieve a natural water balance in the design of the site. Minimise the area of impervious surfaces such as Stormwater drainage is the process of draining excess water from streets, sidewalks, roofs, buildings, and other areas. 25 cfs under the proposed rule compared to 2. For other areas calculations shall be in accordance with AR&R. Guo, Professor, U of Colorado Denver and No. Design Engineer - Registered and licensed Professional Engineer in the State of Louisiana retained by OwnerIDeveloper responsible for the design of a drainage plan. 2 Unit Hydrograph Method 2. 1) The stormwater drainage system is a network of pipes, pits and overland drainage swales which are owned by individual property owners. 5 cfs under existing standards For a half acre site in Brooklyn, the allowable flow would be 1. SECTION 11 - DRAINAGE DESIGN CRITERIA 1. System Plan ♦ 3. • Drainage Area EX-2A is an 11,112 square foot area that consists of the southern portion of the Building 2 parcel. The Colorado Urban Hydrograph Procedure (CUHP) and UDSWM . Design Engineer - Registered and licensed Professional Engineer in the State of Louisiana retained by OwnerIDeveloper responsible for the design of a drainage plan. They can cause sewage overflows on your property during heavy rain. The sizing and construction criteria in this Brief are based on the PA Stormwater BMP Manual (2006) and the PA DEP Model www. Storm Water Detention As-Built Drawing . Private Drainage Easement for Storm Water Detention Plat . Stormwater runoff from this drainage area flows overland and untreated directly into a series of catch basins in the South Street right-of-way, ultimately discharging to the 36” drain in South Street. 25 cfs under the proposed rule compared to 2. A combined sewer is a type of sewer system that collects sanitary sewage and storm water runoff in a single system. If the property owner is unable to attain any written approval from the adjacent downstream property owner(s), the property owner is A drainage basin, or watershed, consists of all drainage areas that contribute flow to an outlet. WETLANDS This section governs natural wetlands (as distinct from stormwater wetland systems that are constructed expressly for stormwater management purposes), when a natural wetland is incorporated in an overall stormwater management scheme. Note: For stormwater vaults larger than typical manholes, the design standards on pages 11-12 “All Underground BMPs and Underground Stormwater Vaults • Sign identifying the facility as a stormwater treatment facility. The inlet is a box of concrete or brick masonry with the clear opening not more than 25mm. Wisconsin Department of Transportation These days, Owen also gives regular 12d training courses in drainage design and macro writing. METHODS OF DETERMINING DESIGN DISCHARGE 2. Design of a stormwater pump station is a complicated procedure because of the large number of parameters that are involved. Most of these storms last for one to two days. 5 Watercourses and Open Channels 13 8 SAFETY IN DESIGN 14 9 MANAGEMENT OF STORMWATER FROM DEVELOPMENT 15 9. This report serves as documentation of all the design flow rates tributary to the Grant Road Project that will be used to size the recommended drainage improvements included in the roadway design. Here is sample language. Below is a recommended approach to the design of a proposed drainage system: • Complete and review the existing drainage study. " Offsite Drainage Areas: The WQv shall be based on the impervious cover of the proposed site. 00, relating to stormwater. nection’, with the objective being to minimise volumes of stormwater diverted to reticulation. Department of Public Works . 1 To see examples of existing rate structures for towns that have established stormwater enterprise funds, refer to the Massachusetts Stormwater Fee Summary sheet. Efficient drainage design and stormwater management are critical requirements in the design and planning stage of urban development. Environmentally friendly properties may consider utilizing storm water re-use through collection for irrigation and/or toilet use. The designer should determine whether this situation is going to present a problem. 0 References – Provides a list of the documents referenced by this section. 2. 1. Enhanced Dry Swale. 1 Construction Activities Stormwater Manual (PDF, 348KB) Last Updated: 6/1/2010 . Note: Information collected during the physical suitability evaluation ( see Step 1 ) should be used to explore the potential for multiple swale practices versus relying on a single facility. Alternatively save yourself the agro and activate the extra features Storm water design for Municipal systems is based on the Hydraulic Grade line, which takes into account all losses in the system. Care is needed to ensure that provided to collect this stormwater from the paved surfaces, parks, landscaped and open space areas, and transfer it to underground pipe drains. The Queensland Urban Drainage Manual (QUDM) shall be the basis for design of stormwater drainage except where amended by this Guideline. ii FOREWARD The information presented in this manual is to be used for the preparation of drainage reports, flood studies, engineered plans, and other stormwater related analyses required by the City of Flagstaff. 3 Plumbing and drainage Part 3: - Stormwater drainage & Section 2 of. Most aspects of storm drain design such as system planning, pavement drainage, gutter flow Sizing the design flow. alternatives to managing stormwater, including roof gardens, permeable paving surfaces and rain gardens. Report Date Dec 2016 6. In almost every location, this water will contain mixed solids, grit or sediment, and some form of chemical/ hydrocarbon or mineral contaminants. AS/NZS 3500. While the full Technical Reference Manual, as referenced in the ordinance, will be included in the appendices of this manual, this chapter will provide a comprehensive review of the stormwater program requirements. Design examples 6. ln I(30) = 4. A relatively impermeable soil layer was found at a depth of 6. 1. A drainage system includes constructed and/or natural features that work together to collect, convey, channel, hold, inhibit, retain, detain, infiltrate, divert, treat, or filter storm water runoff, including detention and retention basins, overland flow paths, pipes, channels, and the inlets and Our advanced drainage design systems are created by experienced drainage specifiers and engineers who can build custom catch basin designs based on your requirements. 2016 Drainage Design and Erosion Control Manual. Proper highway drainage design will help to reduce many of the effects of an inadequate roaddrainage system, including: • water flowing from the roadway onto adjacent properties New Jersey Stormwater Best Management Practices Manual • Appendix C: Sample Municipal Stormwater Management Plan • February 2004 • Page C-3 Introduction Every plan should include an introduction to identify why the plan is being prepared and a summary of the contents of the plan. Utility Conflicts ♦ 6. This manual provides design and guidance on designing and implementing stormwater management practices that will manage rainfall on site in accordance with West Virginia's small Municipal Separate Storm Sewer System (MS4) general permit. 02 7. Impervious surfaces (ie. The Queensland Urban Drainage Manual (QUDM) shall be the basis for the design of stormwater drainage, except as amended by these manuals. • Maximum spread of 6 feet in a travel lane based on a rainfall intensity of 4 inches/hour. 5 cfs under existing standards For a half acre site in Brooklyn, the allowable flow would be 1. Construction ♦ 7. 1. 3 Purpose This planning scheme policy is about the design of stormwater drainage systems (quantity). 10) 1. 2. A. 6. Infiltration System 4 Revised 6/3/2019. Design Storm, 10-Year Event - A runoff, rainfall or flood event, having a ten percent (1 0%) chance of occurring in any given storm event. GENERAL 2. CONCLUSION A storm water detention system will be designed and constructed to meet and exceed the City’s Storm Drainage Design Criteria. 7698 I(30) = 117. They are placed at a depth of 1. Indiana LTAP Stormwater Drainage Manual – Revised February 2008 Chapter 1 - 2 Chapter 3 presents the phenomenon of runoff and its estimation, which is the most important aspect of drainage design. The objectives of stormwater drainage design are as follows: (a) To collect and convey stormwater from a catchment to its receiving waters with minimal nuisance, Stormwater Design Manual Page 1 Town of Clayton, NC - Stormwater Design Manual June 2010 Section 1 – INTRODUCTION & GENERAL GUIDELINES (Last revised 6. 4 Flood Routing 3. The challenges faced by those involved in highway drainage design around the country in meeting these objectives are compounded by the difficulty of selecting the proper BMPs for post-construction and the availability of land in highly developed urban environments. example of stormwater drainage design